Energizer Duo software suffers backdoor Trojan bother

A Trojan backdoor found its way into Energizer Duo USB battery charger software downloads.

Malware bundled in a charger-monitoring software download package opens up a back door on compromised Windows PCs. The contaminated file is automatically downloaded from the manfacturer's website during the installation process, not bundled with an installation CD.

Symantec warns that a file called “Arucer.dll”, which it identifies as Trojan-Arugizer, that is installed on compromised systems is capable of all manner of mischief. This includes sending files to the remote attacker or downloading other strains of malware, as instructed via commands on a back channel controlled by hackers.

It's unclear how long the potentially malicious file has been offered up for public download or how many have been infected, as a write-up on the threat by Symantec explains.

We were interested in finding out how long this file had been available to the public. The compile time for the file is May 10, 2007. It is impossible to say for sure that this Trojan has always been in this software, but from our initial inspection it appears so. We also suspected that the entire file may have been inserted into the package without the creator’s knowledge, but upon closer inspection we discovered the DLL checks for the USB device.

In a statement, Energizer acknowledged the problem and discontinued sale of the affected device, the Duo Charger (Model CHUSB). The battery maker has also launched an investigation into how backdoor functionality found its way into its software.

Energizer has discontinued sale of this product and has removed the site to download the software. In addition, the company is directing consumers that downloaded the Windows version of the software to uninstall or otherwise remove the software from your computer. This will eliminate the vulnerability. In addition CERT and Energizer recommend that users remove a file that may remain after the software has been removed. The file name is Arucer.dll, which can be found in the Window system32 directory.

Energizer is currently working with both CERT and U.S. government officials to understand how the code was inserted in the software. Additional technical information can be found at http://www.kb.cert.org/vuls/id/154421.

US CERT has published an advisory warning of the problem and advising users to either uninstall the software or apply workarounds, as explained here. ®